Centrifugal liquid atomizer



Jan. 10, 1928. I 1,655,932

F. WREESMANN I CENTRIFUGAL LIQUID ATOHIZER Filed Aug.;1;9. 192a MAM. mean INVAIVTb/C Patented Jan. 10, 1928 UNITED STATES FERDINAND WIREESMANN, (ll? MUNICH, GERMANY.

CENTRIFUGAL LIQUID ATOMIZER.

application filed August 19, 1926, Serial No.

My present invention relates to a method and apparatus for atomizing liquids or semiliquid substances, and has particular reference to a method and apparatus for accomplishing an exceedingly line atomization by mechanical means.

My invention contemplates the atomization of liquids for such purposes as moistening air or other gas with water or other liquids; washing and cooling gases; cooling liquids; evaporating the volatile constitucuts of solutions, emulsions, or suspensions, such as milk; drying the solid components entirely or partially; cooling substances s which are liquid when hot and solid when cold so as to solidify them in their atomized state and convert them into a pulverized condition, as for instance, fats, soaps, molten metals, etc. In all of these cases, it is de sir-able to atomize the liquids to the finest possible degree, because by thus enlarging the exposed surfaces of the liquid, the effect desired is enhanced and quickened.

Tn the known processes for atomizing 2a liquids, the small drops thrown off are not of equal dimensions. Inasmuch as the larger one fly further than the smaller ones, the danger exists that some of the particles reunite with each other. This interferes with proper atomization; for example, larger drops are more difiicult to dry than smaller ones. To obviate this danger, the atomization by rotary devices has been accompanied by the blowing of air either above and/or air being blown along directions which define planes lying parallel to the plane of the liquid. This has been done in an attempt to increase the range of the spread material and thereby prevent, the recombining of drops. However, this end is not completely attained since the parallel planes of air flow outside of and not across or into the layer of the atomized liquid.

One object of my invention is to effect an increased degree of atomization while at the same time providing for a more efficient spreading of the liquid being treated. My invention is based upon a cognizance of-the fact that the atomization of liquids by rotary atomizers is effected by the influence upon the liquid of the surrounding air or as. The gaseous medium tears the liquid into very fine drops. Thus, in a vacuum medium, no atomization takes place, and the below the plane of the atomized liquid, the.

alone eflects an efiicient atomization, it fol- 130,335, and in Germany November 13, 1924.

same is true when the atomizer is rotated at a very slow speed, for under such conditions the influence of the surrounding gas upon the spread liquid is greatly diminished.

Accordingly, it is well known that a centrifugal atomizi ng device must be driven very rapidly. However, there have always been present two grave obstacles which have not been heretofore sufficiently appreciated. One of these lies in the fact that the rotation of an atomizer frictionally causes also the surrounding gas itself torotate. The other obstacles lies in the fact that the centrifugal device throws off not only the liquid but also the surrounding gas, thereby creating a low pressure around the device. These conditions reduce the effect of the gas upon the liquid thrown off and thereby impair the efliciency of atomization,

In accordance with my invention, the following three advantageous conditions are attained: (1) The liquid being treated is thrown off, by a very rapidly rotating centrifugal atomizer, in such a manner as to offer the air or gaseous medium the largest and most efi'ective surface for attack while at the same time offering a minimum resistance to the tearing action of the gas. (2) My arrangement is such that the strongest attack of the gas is effected at the very point or points at which the liquid is thrown ofl". (3) The atomized liquid is immediately mixed with the gas streams, spread out, and carried ofl' from the centrifugal device.

Inasmuch as each of the above conditions which are substantially perpendicular to the plane of the spread liquid. By throwing oil the liquid material in this manner, the streams permit themselves to be encountered by the gas in a broadside manner and at the same time offer but little resistance to no the gas, thereby permitting the latter to tear them apart in a most effective manner. (2) By means of separate conduits or duct-s, air or gas under pressure is conveyed to the points where the liquid is thrown off. One

arran ement provides for the passage and directing of gas under pressure through the interior of the rotating casing and to outlet openings at the periphery of the casing, these outlet openings alternating inposition with the liquid outlet openings or slots. Another arrangement provides for the directing of gas or air through annular openings arranged adjacent to the periphery of the casing, the gas being directed from above or below the casing, or both. In this manner the thrown-off streams of liquid are attaclred by the air or gas in a most effective manner at the point or points at which they leave the casing. The forcibly directed gas mixes with the atomized liquid and carries it away, thereby preventing the reuniting of smaller drops into lar er ones, and this effect may be enhanced if t e reaction chamber is rovided with pressure below atmospheric.

his is the ease, for instance, when. gaseous drying means, such as hot air, is drawn by suction from the drying chamber and circulated through the plant. ('3) Additional air or gas under pressure is directed through additional annular openings adjacent to the casing periphery so as to encounter the thrown-off liquid material at an angle and:

thus 'efl'ect'the carrying away of the atomized liquid in all directions.

In one embodiment, the outlet openings or slots throu h which the liquid streams emerge are afjustable, either manually or otherwise, so as to permit widening or closiriiig of the slots. This adjustment may be e ected by automatic means dependent upon the pressure of the emerging liquid and the effect of the centrifugal force.

In the accompan ing drawings, illustrating several forms 0 my invention,-

Fig. 1 is a plan view of a centrifugal atomizer wherein the gaseous medium assing therethrough is directed thereinto rom above;

Fig. 2 is a vertical cross-section substantially through the center of a centrifugal atomizer; and

Figs. 3 and 4 are plan views respectively of superposed elements comprising a centrifugal atomizer wherein adjustable exit openings for the liquid are rovided.

Referring to Figs. 1 an 2, a-casing an is provided, mounted for rotation upon a shaft the latter being journaled upon the base 0. Within the latter, the driving apparatus (not shown) is arranged, comprising, for example, an electric motor, a steam turbine, or the like. The atomizer is adapted to receive li uid substantially centrally thereof, the liqui being fed through a central inlet openin (1 through the supply line or pipe 6. The li uid may also be conveyed in other ways, as or example, by constructing the shaft 6 as a hollow shaft. In such an event, the central opening at is not provided.

The gas under pressure which is to be directed through the atomizer itself is guided thereinto through the openings 7 provided in the upper surface of the casing, thereafter being directed through the ducts g to the outlet openings h. The latter are arranged along the peripheral edge of the casing in such a manner that each thereof is positioned adjacent to one of the vertical outle't slots i for the liquid. This mutual arrangement of the outlet openings enables the outflowing gas at once to hit the outflowing adjacent liquid stream in a broadside manner.

Additional compressed air or gas is guided from above or below, or from both points, through ducts n to the annular outlet openings k and Z.

An additional duct or ducts m permits additional gas to be blown through a similarly arranged outlet opening adjacent to the periphery of the casin for increasing the spread of the atomize liquid.

In Figs. 3 and 4 I have shown a centrifugal atomizer wherein 0 represents a cover plate provided with an inlet opening d and inlet gas opening A rotating table or disc at is fixedly arranged below the cover 0, and these two elements are so arranged that a circular space p is provided between them to receive the entering liquid. From the space 17, the liquid is guided through the radiating passages g to the vertical exit slots In this embodiment, one of the side Walls r of the passages g is relatively fixed, while the opposite walls 8 is movable or adjustable. The walls of the space 1) and of the passages g separatethe liquid from the compressed gas. The movable or adjustable walls .9 may be arranged to move themselves automatically under the pressure of the liquid and the effect of the centrifugal force, or they may be regulated by hand or by other mechanism so as to effect an adjustment of the exit openin z.

. I ela 1d1:

1. In a centrifugal liquid atomizer, a rotating casing adapted to receive the liquid to be atomized substantially centrally thereof, said casing being provided with substantially radial passa es terminating in openings arranged on t e casing periphery, said openings being so shaped that the liquid ejected therefrom will emerge in planes substantially parallel to the axis of rotation, and means for directing a gas under pressure past said periphery and along oblique directions with respect to the axis of rotation, said last named means comprising a duct terminating in an annular outlet opening adjacent to said periphery.

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2. In a centrifugal liquid atomizer, a rotating casing adapted to receive the liquid to be atomized substantially centrally thereof, said casing being provided with substantially radial passages terminating in openings arranged on the casing periphery, said openings being so shaped that the liquid ejected therefrom will emerge in planes substantially parallel to the axis of rotation, and said passages having relatively adjustable side walls for altering the size and shape characteristics of said openings.

3. In a centrifugal liquid atomizer, a rotating casing adapted to receive the liquid to be atomized substantially centrally thereof, said casing being provided with substantially radial passa es terminating in openings arranged on the casing periphery, said openings being so shaped that the liquid ejected therefrom will emerge in planes substantially parallel to the axis of rotation, and means for directing gas under pressure in substantially radial directions from said casing, said last named means comprisingsubstantially radial ducts terminating at their inner ends in openings arranged in a side wall of the casing and terminating at their other ends in outlet openings arranged along the casing periphery in alternate positional relationship with respect to the liquid openi. In a centrifugal liquid atomizer, a 1'0- tating casing adapted to receive the liquid to be atomized substantially centrally thereof, said casing being provided with substantially radial passages terminating in openings arranged on the casing periphery, said openings being so shaped that the liquid ejected therefrom will emerge in planes substantially parallel to the axis of rotation, and means for directing gas under pressure in substantially radial directions from said casing, said last named means including substantially radial ducts terminating at the casing periphery in outlet openings adjacent to the first named openings, the gas outlet openings comprising slots arranged substantially perpendicularly to the liquid openings;

5. In a centrifugal liquid atomizer, a rotating casing adapted to receive the liquid to be atomized substantially centrally thereof, said casing being provided with substantially radial passages terminating in openings ar ranged on the casing periphery, said openings being so shaped that the liquid ejected therefrom will emerge in planes substantially parallel to the axis of rotation, and means for directing a gas under pressure past said periphery and along oblique directions with respect to the axis of rotation, said last named means comprising a series of ducts terminating in a set of adjacently arranged annular openings adjacent to the casing periphery, whereby the gas emer ing from said annular openings will en ance the spread and atomization of he liquid streams.

6. In a centrifugal liquid atomizer, a rotating casing adapted to receive the liquid to be atomized substantiall centrally thereof, said casing being provi ed with substantially radial passages terminating in openings arranged on the casing periphery, said openings being so shaped that the liquid ejected therefrom will emerge in planes sub stantially parallel to the axis of rotation, means for directing a gas under pressure in substantially radial directions from said casing said last named means including substantially radial ducts terminating at the casing periphery in outlet openings adjacent to the first named openings, and means for directing a gas under pressure past said pe riphery along oblique directions with respect to the axis of rotation, said last named means including a duct terminating in an annular-outlet opening adjacent to the casing periphery. V y

In testimony whereof I hereunto afiix my signature.

FERDINAND WREESMANN. 

